Semiconducting icosahedral boron arsenide crystal growth for neutron detection

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• 作者：C.E. Whiteley^a ; ^{clintonw@ksu.edu} ; Y. Zhang^a ; Y. Gong^b ; S. Bakalova^b ; A. Mayo^a ; J.H. Edgar^a ; M. Kuball^b
• 关键词：A2. Growth from high temperature solutions ; A2. Growth from solutions ; B2. Semiconducting III&#x2013 ; V materials
• 刊名：Journal of Crystal Growth
• 出版年：2011
• 出版时间：1 March 2011
• 年：2011
• 卷：318
• 期：1
• 页码：553-557
• 全文大小：691 K

文摘

Semiconducting icosahedral boron arsenide, B₁₂As₂, is an excellent candidate for neutron detectors, thermoelectric converters, and radioisotope batteries, for which high quality single crystals are required. Thus, the present study was undertaken to grow B₁₂As₂ crystals by precipitation from metal solutions (nickel) saturated with elemental boron (or B₁₂As₂ powder) and arsenic in a sealed quartz ampoule. B₁₂As₂ crystals of 10–15 mm were produced when a homogeneous mixture of the three elements was held at 1150 °C for 48–72 h and slowly cooled (3.5 °C/h). The crystals varied in color and transparency from black and opaque to clear and transparent. X-ray topography (XRT), and elemental analysis by energy dispersive X-ray spectroscopy (EDS) confirmed that the crystals had the expected rhombohedral structure and chemical stoichiometry. The concentrations of residual impurities (nickel, carbon, etc.) were low, as measured by Raman spectroscopy and secondary ion mass spectrometry (SIMS). Additionally, low etch-pit densities (4.4×10⁷ cm⁻²) were observed after etching in molten KOH at 500 °C. Thus, the flux growth method is viable for growing large, high-quality B₁₂As₂ crystals.